Safety device for punch presses and the like



Jan. 30, 1923.. 1,443,791. .I. KRATUCHVIL.

SAFETY DEVICE FOR PUNCH PRESSES AND THE LIKE.

FILED MAY 29, 1920. I 3 SHEETS-SHEET l.

Jan. 30, 1923.

J. KRATOCHVIL.

SAFETY DEVICE FOR PUNCH PRESSES AND THE LIKE.

.3 SHEETS-SHEET 2.

FILED MAY 29. I920.

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1. KRATOCHVIL.

FILED MAY 29. I920. 3 SH: EEEEEEEEEE x if Irma??? b llatented ,lan, Ell, 1 323,

isldtfitll l l llig JOHN KRA'IOCHVIL, OF IVIAYNOOD, ILLIIJOIE, ASSIGNOR T0 AMERICAN CAN COMPANY, OF IiTEVT YORK, N. 'Y., A COBPOBA'IIDN G1 KEV] JERSEY.

SAFETY DEVICE FOR PUNCH PEESSES AND THE LIKE.

Application filed May 29, 1920.

T 0 all whom it may concern:

Be it known that 1, JOHN Kiuxroorrvin, a citizen of the United States, residing in Maywood, in the county of Cook and State of illinois, have invented a new and useful. improvement in Safety Devices for Punch Presses and the like, of which the following is a speciiicatioi'i.

This invention relates in general to feed ing mechanism for punchpresses and the like, and has more particular reference to feeding mechanism, wherein a strip of sheet metal is fed into a punch press to have a number of articles formed therefrom by successive action of the die parts.

It will, however, be manifest, that with slight changes, the invention may be used for feeding sheet metal to other forms of punch presses and to other types of machines.

My present invention, however, while usable in connection with other and dillerent apparatus, has more particular reference, particularly as embodied for the purposes of illustration in this specification, to the apparatus shown, described and claimed in ap plication for patent Serial No. 385,203, filed May 29, 1920, by Hugo Schoendelen, for improvements in safety devices for punch presses and the like.

A principal object of the present invention is the provision of mechanism and devices for feeding the metal into operative relation with a press or other apparatus, from which articles are delivered into a chute, or other receptacle or delivering mechanism, so constructed, arranged and controlled, that the feeding action will cease when the condi tions in the chute, receptacle or other deli'w ering or receiving device, are unfavorable for further action of the press or apparatus. My invention contemplates in this connection, a provision of means for rendering the active f eding part inoperative or without effect, when the chute is clogged or the re ceptacle too full to receive additional articles. 7

Numerous other objects and advantages of the invention will be apparent, as it is better understood from the following description, which taken in connection with the accoinpanying drawings, discloses a preferred embodiment thereof.

1 is an end elevation of a press equipped with my invention;

Serial No. 385,148.

F 52 is a front elevation thereof; and

3 is an enlarged partial perspective view of a portion of said apparatus.

The apparatus shown on the drawings and selected for the purpose of illustration, is a punch press adapted to form artieles such as can ends, from strip material. The strips are autoinatically fed into a po sition, from which they may be advanced to the dies, by progressive steps, each step occurring after a die action and being wholly automatic in action. A number of can ends or covers are fo 'ined from each strip and the apparatus is so constructed and arranged, that after every descent of the die, a strip is advanced an appropriate distance, to present the part of the strip from which the next article is to he formed. T he apparatus also provides for the feeding of the strips in such manner as to cause them to be tal-zen singly from the stack and to follow each other closely past the dies, so that the dies may reciprocate continuously and without interruption.

In this action, the strips are picked up from the dies by suction heads, which arrange them opposite a slot into which they are thrust sidewise by pusher blocks. Arriving in the slot, each sheet is fed forward with a step-by-step movement between the dies. Means are provided in the ap paratus for preventing the feeding to the die, should more than a single blank be positioned in the slot, and to stop the feeding action under other adverse conditions.

The apparatus comprises a support 11, carrying a press bed or frame 12, inwhich arc n'iounted the operative parts. The bed extends up at one side to provide the two standards 13, providing the guides 1-1, for the upper reciprocating; die head 15 at the top, these standards are provided with bearings 16, for the shaft 17, which is the main power shaft and which carries the pulley 18 to actuate the apparatus. The shaft 17 is a crank shaft having a crank 17 and the die head 15 is moved up and down between the guides by the action of said crank in the usual manner. it stack holder 19 is positioned on the bed and at a side thereof and is adapted to contain astack of blanks or strips to be operated upon,'such blanks or strips being indicated at 21. These blanks are lifted or moved singly from the. stack by three suction heads 2:2, mounted upon the end of reciprocating rods or pipes xially movable through bearings 2%, er; idiiig up from the bed. The pipes 23 are connected by pipes 91" and couplings 23 to form a unitary structure an. the pipes 23 and and the coupl are hollow and in communication throu valve structure 26, with vacuum or e7-1h pipe 28. The valve 26 is controlled a slide rod 29, positioned on th suction head and operabl; by a the head contacts therewi' The suction mechani caused to reciprocate a ing a slot in its upper end pin 3%, upon a lever be, 4 i d :1 the bed and connected by a. link 1 a crank dish 38 fixed upon a stub This shaft also carries a gear l, n with a pinion 4-2, upon a stub shalt Y driven by a gear meshing with a pnnon Reciprocation is imparted to the push rods from ashatt 49 through arms or links The shaft 49 is mounted in bearings is connected by an arm 53 and the link with abell crank lever pivotei. on the stud shatt This lever carries a re 56 engaging the cam 57 on the shaft 39, the roller being held against the cam by a spring 58, which sprin actuates the pusher blocks in the operative stroke.

Thereafter, the sheets are fed along the slot and between the dies. by mechanism which need not be described in detail, since it forms no part on my pres invention. It may be mentioned, hov-iovcr, that this mechanism is driven from a. crank disk {3? and connecting rod 62.

After the articles are formed by the dies. they are fed into a receiving chute or r ceptacle 63, and may be seen in Fig. 3, where reference character 6% indicates the formed can end, produced in the present instance. Means are provided in accordance with r invention, to cause the feeding act-ion to cease, when the articles or ends clog the chute and pile up to an Xtent to interfere with the die action. The pusher bloc-l; shafts l? are provided with bloci or stops 65 and the arms 66 are pivoted upon the bearings 24c to normally rest on the shafts 4? and behind the stop blocks 65. On each nae-3,791

end of the trip be deter ned or not picked up, the arm will not be liftel and both pusher blocks will be prev nte'l from being moved on a pushing stroke under the tion of the s :ing 78 The rods rather se'tety device roi, provided to are (it special COPfl ions sin-cc tl in onnnuric:

tion heads all eiie X oi? the suction ternally, the brcal head. prevents ap the others. The l'O(j 2 is provided to msh suction head and pusher under certain feeding which, since they form no part 0; A

DIS 1 invention, are not thought to r planation. The red at the rigl figure and shown ii enla. Fig. is provided to brc the righ hand suction head, a the litti of the right hand press is cl it lever 70 TO on the hand bed or :ti .k and has one end [1 er'tending' own and adapted to be i formed pile therein. tends over and above rod 67 and events th's by a sh as the result the suction heads.

=fi heu the lever is in normal position, i. e., when the end 71 which is heavier is in lower position the rod (37 moves upward in the oosition shown in F 3, as the she t ap- :roaches the slot, the collar liil tii the ever (56 out of the way of the stop l cl: 5. JYhen however, the chute is clogged, the

lever 68 prevents movement of the rod 6?. PHSlHDQ' tile sheet away from the suction head as the suction head approaches the upper end of its stroke, thereby permittinga so the arm (36 to re t in. position hchind and in the path (it the stop block This preinto the slot,

vents any feeding of the sheets until the chute is clear and the .19 are so dimensioned and arranged that thi. interruption ot the feeding; action will occur while the chute may still receive the additional articles to be iti'irmed by the strip or strips alre dy within the slot.

It is thought that the invention and many of its attendant advantages will be understood trom the foregoing description, and it Will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described, being merely a preferred embodiment thereof.

I claim:

1. In a feeding mechanism for die presses and the like, the combination of a feed way, a stack of blanks arranged adjacent said feed way, means for feeding blanks to the press, means for discharging formed articles from the press, and means operable by articles in the discharge means for preventing feeding action when the discharge mechanism is clogged, said discharging means having walls within which the clieformed articles are collected and are caused to accumulate in a pile of increasing height in case of any obstacle to the taking away of said articles.

2. In a feeding mechanism for die presses and the like, the combination of a feed way, a stack holder adjacent thereto, means for transferring blanks from said stack to said feed way, a discharge device from the press,

and means operable by articles in the dis.

charge device for preventing the action of said transferring means when the articles in said discharge device prevent free discharge from the press, said discharge device having article-confining walls within which the die-formed articles are collected and are caused to accumulate in apile of increasing height in case of any obstacle to the taking away of said articles.

25. In a feeding mechanismfor die presses and the like, the combination of a stack holder for blanks, means delivering blanks singly from said stack holder, a chute for collecting finished articles and having upwardly extending walls to contain said articles in a pile, and means over said chute and operable by finished articles accumu lated therein for interrupting said feeding means.

a. In a feeding mechanism for die presses and the like, the combination of a stack holder for blanks, suction means: selecting blanks singly from said stack holder and moving them into position to be fed between the dies, a chute for collecting finished articles and having upwardly extending walls to contain said articles in a pile, and means over said chute and operable by finished articles accumulated therein for reducing said suction means.

5. In a feeding mechanism for die presse. and the like, the combination of a stack holder for blanks, means singly selecting blanks from the stack holder, a chute for collecting finished articles and having upwardly extending walls to contain said articles in a pile, and means over said chute and operable by finished articles accumulated therein for separating a blank from lated therein for obstructing the feeding movement.

7. In a feeding mechanism for die presses and the like, the combination of a stack holder for blanks, suction means for selecting blanks from the stack, devices for feeding the selected blanks and means pushing the blanks from the suction means and positively obstructing the feeding movement when the delivery from the press is clogged.

.8. In a feeding mechanism for die presses and the like, the combination of a stack holder for blanks, a reciprocating suction. head for lifting the blank from said stack holder, a rod movable by the blank, when lifted by the suction head, and means operable by accumulated articles formed by the .press, for preventing movement of the rod and resulting in separation of the blank from the suction head.

9. In a feeding mechanism for die presses and the like, the combination of a suction head for moving the blanks into feeding position, member movable by the blank, while carried on said suction head, and means operable through the agency by accumulated articles formed by the press, for preventing movement of said member'to cause separation of the blank and suction head.

10. In a feeding mechanism for die presses and the like, the combination of a stack holder for blanks, reciprocating means for moving the blanks in the feeding action, a member positioned in the path of movement of said reciprocating means and lifted out of the way thereof in the normal feeding action, and means operable through the agency of accumulated articles formed by said press, for preventing the lifting of said member.

JOHN KRATOCHVIL. 

